/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.giraph.graph.partition;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

import org.apache.giraph.graph.BspUtils;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;

/**
 * Hint to the {@link RangeMasterPartitioner} about how a
 * {@link RangePartitionOwner} can be split.
 *
 * @param <I> Vertex index to split around
 */
@SuppressWarnings("rawtypes")
public class RangeSplitHint<I extends WritableComparable>
        implements Writable, Configurable {
    /** Hinted split index */
    private I splitIndex;
    /** Number of vertices in this range before the split */
    private long preSplitVertexCount;
    /** Number of vertices in this range after the split */
    private long postSplitVertexCount;
    /** Configuration */
    private Configuration conf;

    @Override
    public void readFields(DataInput input) throws IOException {
        splitIndex = BspUtils.<I>createVertexIndex(conf);
        splitIndex.readFields(input);
        preSplitVertexCount = input.readLong();
        postSplitVertexCount = input.readLong();
    }

    @Override
    public void write(DataOutput output) throws IOException {
        splitIndex.write(output);
        output.writeLong(preSplitVertexCount);
        output.writeLong(postSplitVertexCount);
    }

    @Override
    public Configuration getConf() {
        return conf;
    }

    @Override
    public void setConf(Configuration conf) {
        this.conf = conf;
    }
}
